Tunnel, furnace, kiln, oven, and the like



Oct 13, 1925 H. FRANCART 10mm., runnen. x1Lu,'ovn, man 'run LIKE Henr/ /r/'czncar /V Vf/V TOI? 5 MAM/g -..lill

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Paten-ted Oct. 13, 1925.

HENRI FRANCART, OIE` TONGRES, BELGIUM.

TUNNEL, FURNACE, KILN, OVEN, AND THE LIKE.

Application filed June 24, 1920. Serial N'o. 391,513.

(GRANTED UNDER THE PROVISIONS F THE ACT 0F MARCH 3, 1921, 41 STAT. L., 1313.)

To all 'whom il" mag/concern:

Be it known that I, HENRI FRANcAnT, citi- Zen of Belgium, residing at Tongres, Belgium, have invented certain new and useful Improvements in or Relating to Tunnels,

Furnaces, Kilns, Ovens, and the like, of

which the following is ay specification.

The present invention relates to rectilinear1 and circular tunnel ovens, and its object is i to diminish considerably the losses due to radiation in the high tempera-ture zone, whilst allowing of the displacement of the gaseous mass from the cooling zone to the preheating zone without any loss of temperature, although these two zones may be necessarily separated from each other by the cooking or drying zone.

The invention consists in providingr around the tunnel, at the point where the drying takes place at a high temperature a second tunnel surrounding thefirst in such manner as to form between the two tunnels an empty space in which a gaseous mass is caused to circulate at a temperature lower than that required to effect drying, the gaseous mass coming from the cooling zone so as to pass to the preheated zone.

The inner tunnel is fitted with insulating parts, regulated at will, in such a way that the heat lost in the jacket tunnel, by external radiation, corresponds approximately to tlhe heat transmitted by ythe j acketed tunnel. By this arrangement the gaseousV mixture may be transferred from the cooling zone to the preheated zone without ra fall in temperature, and the loss by radiation externally is reduced to that of an oven where the drying temperature would be lower by some hundreds of degrees.

In order to control the quantity of gas sucked up into the jacket-tunnel, a valve is placed between the drying zone and the cooling zone. At the outlet from the jacket tunnel the gases may be mixed with gas coming from the acketed tunnel.

Figures 1 and 2 of the accompanying drawing shew by way of example, a constructional form of the invention.

Referring t0 the drawing, the high temperature Zone of the tunnel 1 through which the trucks 2 pass loaded with the articles to be heated is surrounded by a tunnel 3, so that a space 4 is formed between the two tunnels 1 and 3 in which space some of the warm air circulates which has served to cool the heated articles. The air enters into the space 4 through a damper or valve controlled opening 5 and flows therefrom tothe preheating or drying zone indicated at 6 Where the air becomes mixed with the products of combustion. Y

1n order to correct inequalities in the thickness of the roof of the inner tunnel and the radiating surface thereon, the outer roof' of the oven may be provided with passageways or openings 8 through which heat insulating material such as sand 7 can be delivered onto the top of the inner tunnel, thus considerably increasing the thickness of the roof of the inner tunnel and thereby diminishing the radiating effect. The passage-ways or openings 8 may be closed by suit-able covers 9. Beneath the inner tunnel fioor are provided gas conductors 10 which deliver the gas to suitable burners 11 ar-l ranged at or near the tunnel floor level. The adjustment and corrections required to maintain the necessary volume of the gaseous' mass can be effected by a damper 12 shown in dotted lines to the right of Fig. 2, which damper 12 is arranged at the entrance to the space 4 between the cooling zone and the high temperature zone.

The air first traverses the cooling zone at the right of Fig. 2 which zone is fitted according to the arrangement shown in a copending application, Ser. No. 391,512. The dan'iper controlled opening 5 is situated at the upper part of the central part ofthe oven where the air affects its asc-entional movenient. Accordingly part of the air would penetrate through opening 5 into space 4, and flow therefrom to the p-reheating Zcne indicated by 6. The pr'eheating zone is fit-ted according to arrangement sho-Wn in the 95 above cio-pending application. The air passing through space 4 absorbs the heat radiating from the cooking zone and transmits it t0 the preheating zone.

Having now particularly described and 5 ascertained the. nature of my said invention and in what manner the same is to be performed, I declare that what I claim is In a tunnel oven, a jacket oven, a drying oven Within the jacket ovenand forming therewith a free space for passage of air, said 10 jacket oven having openings therein through which heat insulating material may be applied tothe surface of the drying oven.

In testimony whereof I affix my signature.

HENRI FRANCART. 

